Related papers: Metallicity of the intergalactic medium using pixe…
The circumgalactic medium (CGM) remains one of the least constrained components of galaxies and as such has significant potential for advancing galaxy formation theories. In this work, we vary the extragalactic ultraviolet background for a…
We present a study of the galaxy environment of 9 strong HI+CIV absorption line systems ($16.2<{\rm log}(N({\rm HI}))<21.2$) spanning a wide range in metallicity at $z\sim4-5$, using MUSE integral field and X-Shooter spectroscopic data…
We search for OVI absorption in a Keck HIRES spectrum of the z=3.62 quasar Q1422+231. Comparison of CIV measurements to cosmological simulations shows that \lya forest absorbers with N_HI > 10^{14.5} have [C/H]~=-2.5, for the UV background…
We have analyzed long-slit spectra of 12 dwarf irregular galaxies from the Arecibo Dual Beam Survey (ADBS). These galaxies represent a heterogeneous sample of objects detected by ADBS, but on average are relatively gas-rich,…
We present a study of metal-enriched halo gas traced by MgII and CIV absorption at z<2 in the MUSE Analysis of Gas around Galaxies survey and the Quasar Sightline and Galaxy Evolution survey. Using these large and complete galaxy surveys in…
The wavelength range 912-2000A (hereafter far-UV) provides access to absorption lines of the interstellar medium (ISM), circumgalactic medium (CGM), and intergalactic medium (IGM) in phases spanning a wide range of ionization, density,…
The metal deficient (Z = Z_sun/41) Blue Compact Dwarf Galaxy (BCD) SBS 0335-052 was observed with ISOCAM between 5 and 17 mic. With a L_12mic/L_B ratio of 2.15, the galaxy is unexpectedly bright in the mid-infrared for such a…
We analyze relative abundances and ionization conditions in a strong absorption system at z=6.84, seen in the spectrum of the z=7.54 background quasar ULAS J134208.10+092838.61. Singly ionized C, Si, Fe, Mg, and Al measurements are…
High-resolution spectra of 13 core helium-burning stars in the thick disk of the Galaxy have been obtained with the SOFIN spectrograph on the Nordic Optical Telescope to investigate abundances of up to 22 chemical elements. Abundances of…
We present submillimeter observations of the Local Group, metal-poor, irregular dwarf galaxy IC 10, directly relevant to the interaction between interstellar medium and star formation activity in primeval galaxies. Using the JCMT, we have…
High resolution optical (HIRES/Keck) and UV (STIS/HST) spectra, covering a large range of chemical transitions, are analyzed for three single-cloud weak MgII absorption systems along the line of sight toward the quasar PG 1634+706. Weak…
We have recently used the Hubble Space Telescope to study a pair of high velocity clouds in the direction of Mrk 509 that have unusual ionization properties. They exhibit strong CIV absorption with little or no low ion absorption or HI 21cm…
Correlations are investigated of the outflow strength of quasars, as measured by the blueshift and asymmetry index (BAI) of the CIV line (Wang et al. 2011), with intensities and ratios of broad emission lines, based on composite quasar…
How dust scatters and absorbs starlight in the interstellar medium (ISM) contains important clues about the size and composition of interstellar dust. While the ultraviolet (UV) and visible interstellar extinction is well studied and can be…
Hydrocarbons are ubiquitous in the interstellar medium, observed in diverse environments ranging from diffuse to molecular dark clouds and strong photon-dominated regions near HII regions. Recently, two broad diffuse interstellar bands…
We present mid-infrared maps and preliminary analysis for 61 galaxies observed with the ISOCAM instrument aboard the Infrared Space Observatory. Many of the general features of galaxies observed at optical wavelengths---spiral arms, disks,…
We present a sample of 34 weak metal line absorbers at $z< 0.3$ complied via the simultaneous detections ($3\sigma$) of the SiII$\lambda1260$ and CII$\lambda1334$ absorption lines, with $W_{r}$(SiII)$<0.2$ \AA\ and $W_{r}$(CII)$<0.3$ \AA,…
The COS Legacy Archive Spectroscopic SurveY (CLASSY) HST/COS treasury program provides the first high-resolution spectral catalogue of 45 local high-z analogues in the UV (1200-2000\AA) to investigate their stellar and gas properties. We…
We examine the local density environments around 67 quasars at $z\sim3$, by combining the imaging data of Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) and Canada-France-Hawaii Telescope Large Area U-band Survey (CLAUDS) over about…
We describe an ultraviolet spectroscopic survey of interstellar high-velocity cloud (HVC) absorption in the strong 1206.500 Angstrom line of Si III using the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope. Because…